How to find out what's really going on in your XPages Applications

There are several ways to find out what's
going on in your XPages applications. Some tools like Firebug
are well known, but other tools and features might be a little hidden.

XPages Toolbox

The XPages
Toolbox provides several features
to monitor XPages applications. There is a CPU profiler (see screenshot),
a backend profiler, run time monitoring, a memory inspector and logging
functionality.

Medusa

Medusa
is a Firebug extension. It displays the server side DOM (see screenshot)
and you can type in code in a command line that is executed on the server.

Update: As commented by Nathan
below the current version is not compatible with 8.5.2.

XPages API Inspector

The
XPages API Inspector helps to
find out what Java classes are used on server side for the UI elements
and displays their methods and fields.

Debug Java Code

The big advantage of writing server
side code with Java (instead of server side JavaScript) is that you can
easily debug it. This video
describes how to debug Java code in a NSF.